Radar measurements taken more than a month before a giant sinkhole (pictured) opened up in 2012 in Bayou Corne, Louisiana, reveal that nearby ground shifted horizontally towards the pit's location.

Cathleen Jones and Ronald Blom of NASA's Jet Propulsion Laboratory in Pasadena, California, looked at radar data gathered by an unmanned aircraft as part of a Mississippi River delta study. By comparing data from flight passes in June 2011 and July 2012, the team saw that surface material had moved by as much as 26 centimetres towards where the 110-metre-wide sinkhole appeared in August 2012.

Credit: HEATHER MCCLELLAND/AP/PA

Radar remote sensing could be a way of predicting the formation of these potentially catastrophic sinkholes and their growth rate, the authors say.

Geology http://doi.org/qnr (2013)